Stackfield is available in English and German, including spellchecker.
The language can be set directly at the first login after registration on Stackfield or alternatively in the user account settings. To access your personal account settings, click on your profile picture in the lower left corner of the sidebar and select "My Account". Choose the Profile tab in the following view and find the section Language. Here you can select a different language by clicking on the one that is currently set.
Choose another language by clicking on the current one
Note: If you are using a browser, the language / spellchecker* may need to be adjusted in the browser settings.
*For help click on the "More" button (symbol: "3 dots" or "3 horizontal lines", at the end of the address line of the browser) to find the option Help which leads you to an help center where you can search for the keyword Language.